Velcade treatment of OSCC cells had no significant effect on cell viability at 10 nmbut significantly decreased cell viability at 25 nm,and at 100 nmthe number of viable OSCC cells was negligible (Fig. development and/or progression. Inhibiting the inflammatory pathway by aspirin and the proteasome/NF-B pathway by bortezomib resulted in marked reduction in cell viability in OSCC lines. Taken together our studies indicate a strong link between inflammation and OSCC development and reveal IL-8 as a Ciprofloxacin hydrochloride hydrate potential mediator. Treatment based on prevention of general inflammation and/or the NF-B pathway shows promise in OSCCs. Keywords:Gene Expression, Inflammation, Interleukin, Microarray, NF-B, Anti-inflammatory, Biomarker, Oral Cancer, Meta-analysis == Introduction == Oral squamous cell carcinoma (OSCC)2is the sixth most common cancer and an important public health concern worldwide (1,2), with 405,000 new cases and 211,000 deaths reported annually (3). Patients diagnosed with oral cancer have a particularly low 5-year survival rate due to the compounding factors of late detection and lack of truly effective therapies according to the American Cancer Society and the online Facts page of The Oral Cancer Foundation. Therefore, development of early detection techniques and subsequent innovative therapies are greatly needed. Besides high mortality, OSCC is also often associated with eating difficulties, speech impairment, and general psychological distress (6,7). Tobacco and alcohol consumption, betel quid chewing, and viral infections are some of the known risk factors for OSCC (8,9). In addition, oral infections leading to periodontal diseases are also associated with OSCC (10,11), About 20% of oral leukoplakia undergo malignant transformation and develop into OSCC (6). Chronic inflammation is associated with the development of a Ciprofloxacin hydrochloride hydrate variety of epithelial cancers such as colon and pancreatic cancers (12,13), but whether it plays a significant role in development Ciprofloxacin hydrochloride hydrate of oral cancers is unclear. It is believed that the chronic inflammatory environment causes genomic alterations that eventually lead to tumor development (8,14). Essential components in this association are the cytokines produced by tumor cells themselves as well as by the innate immune cells activated during the inflammatory process (15,16). In the present study we analyzed the roles of inflammatory genes in OSCC by gene expression screening in OSCC cell lines. In common with a Ciprofloxacin hydrochloride hydrate variety of tumor types, these OSCC lines exhibited basally high activity of the NF-B transcription factor, which is consistent with chronic activation of the inflammatory process. The data obtained by gene expression profiling were used to identify common molecular pathways affected in OSCC. Differentially regulated inflammatory genes, growth factors, and their receptors were subjected to further analysis to identify candidate genes that are potential biomarkers and molecular targets in OSCC. To define the clinical relevance of these candidate genes, we performed meta-analysis with a Ciprofloxacin hydrochloride hydrate data base of a large number of human OSCC patient samples (www.ncbi.nlm.nih.gov). This analysis revealed common set of genes involved in inflammation, angiogenesis, and cell cycle. One important gene identified by this strategy wasIL-8. High levels of IL-8 have been found in various human diseases and malignancies (1721). IL-8 levels were found to be highly expressed in saliva of OSCC patients (22). Elevated levels of IL-8 correspond to an increased metastatic potential of melanoma (23), breast (24), renal (25), gastric (26), ovarian (27), pancreatic (28), and colorectal cancers (29). IL-8 overexpression is associated with disease progression of urogenital cancers, including transitional cell carcinoma of bladder (30) and prostate cancer (31,32). IL-8 has been shown to play an important function in growth and tumor development under hypoxic conditions as well (28). These studies clearly signify a role of IL-8 in cancer development and its potential as a therapeutic target. Therefore, IL-8 expression was knocked-down using small-interfering RNA (siRNA) to examine the role of the IL-8 signaling pathway in OSCC. IL-8 knockdown significantly reduced the viability of OSCC cell lines. Furthermore, studies with an anti-inflammatory drug and an NF-B inhibitor further indicated the importance of the inflammatory process in OSCC. == EXPERIMENTAL PROCEDURES == == == == == == Cells and Cell Culture == Human oral keratinocytes (HOK) were obtained from the ScienCell Rabbit Polyclonal to ZADH2 and grown in KBM-2 with supplements (Lonza, Walkersville, MD). Human oral squamous cell carcinoma cells SCC9, SCC15, and SCC25 (ATCC, Manassas, VA) were cultured in DMEM supplemented with 10% fetal calf serum, 100 g/ml penicillin, and 100 g/ml streptomycin. Cells were passaged twice a week. == NF-B.
